Abstract: INRYCO, Inc. was formed through the mergers of Joseph T. Ryerson Co. in Chicago; Inland Steel Co. in Chicago, and the Milwaukee Corrugating Company, among other firms acquired. Ryerson was founded in 1842, Inland Steel in 1893, and Milwaukee Corrugating Company in 1902.

Louis Kuehn established a corrugating company in La Crosse, WI, but in 1902, he sold the firm and relocated to Milwaukee where, with the help of the Pritzlaff Hardware family, he founded Milwaukee Corrugating. Initially, it produced corrugated steel siding but quickly expanded its product line to include a variety of goods for the hardware and sheet metal trades such as steel roof tiles and stamped metal ceilings. By the 1920s it was one of the country’s leading building materials manufacturers. In 1930, the company name was changed to Milcor Steel Co., and in 1936 it was purchased by Inland Steel Co. but retained the Milcor name. During WWII, Milcor churned out a wide variety of goods in support of the war effort. In 1948, Milcor was renamed Inland Steel Products Co. In 1968, the company name changed again to Inland-Ryerson Construction Products Co., and in 1975 it was officially changed to INRYCO, Inc.

Scope and Content: The majority of this collection documents the company history during its Milwaukee Corrugating/Milcor years. It contains financial records, reports, company publications, business agreements, ledgers and stock certificate booklets.

Restrictions: None

Administrative Notes: The original collection was donated by INRYCO Architectural Products. Additional material was processed by Luke Frommelt in August 2015.